From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx164.postini.com [74.125.245.164]) by kanga.kvack.org (Postfix) with SMTP id 158B36B005A for ; Wed, 27 Jun 2012 21:18:42 -0400 (EDT) Message-ID: <4FEBB0FA.2070203@kernel.org> Date: Thu, 28 Jun 2012 10:18:50 +0900 From: Minchan Kim MIME-Version: 1.0 Subject: Re: excessive CPU utilization by isolate_freepages? References: <4FEB8237.6030402@sandia.gov> <4FEB9E73.5040709@kernel.org> <4FEBA520.4030205@redhat.com> <4FEBAC42.3030800@kernel.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Rik van Riel , Jim Schutt , Andrew Morton , Mel Gorman , KAMEZAWA Hiroyuki , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "ceph-devel@vger.kernel.org" On 06/28/2012 10:06 AM, David Rientjes wrote: > On Thu, 28 Jun 2012, Minchan Kim wrote: > >>>>>>> https://lkml.org/lkml/2012/6/21/30 >>>>> >>> Not sure if Jim is using memcg; if not, then this won't be helpful. >>> >> >> >> It doesn't related to memcg. >> if compaction_alloc can't find suitable migration target, it returns NULL. >> Then, migrate_pages should be exit. >> > > If isolate_freepages() is going to fail, then this zone should have been > skipped when checking for compaction_suitable(). In Jim's perf output, > compaction_suitable() returns COMPACT_CONTINUE for a transparent hugepage. > Why is zone_watermark_ok(zone, 0 low_wmark + 1024, 0, 0) succeeding if > isolate_freepages() is going to fail? > zone_watermark_ok doesn't consider migratetype but suitable_migrate_target does consider one. > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org > -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org